The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Automatic transmissions often employ sensors to detect a shaft input speed to the transmission. The input speed may be used in various ways to improve the quality and performance of transmission shifts between speed ratios of the transmission. Occasionally, the sensor for the transmission input speed may output a faulty or noisy signal. Such faulty or noisy signals are often inadequate for use in controlling the transmission as desired. A transmission with a faulty sensor may exhibit decreased drivability or may be placed into a “limp-home” mode having reduced transmission performance. Accordingly, there is a need in the art to provide a method and system for improving transmission performance when a transmission speed input sensor fails.